Improved screw-wrench



UNITED STATES PATENT OEEICE.

GEORGE O. TAFT, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO THOMAS H.DODGE, OF NASHUA, NEW HAMPSHIRE.

IMPROVED SCREWl-WRENCH.

Specification forming part of Letters Patent No. 41,747, dated February23, 1864.

.To all whom it may concernY Be it known that I, GEORGE C. TAE'r, of thecity and count-y of Worcester, and State of Massachusetts, have inventeda certain new and useful Improvement in Screw-Wrenches 5 and I do herebydeclare that the following is a f ull, clear, and exact description ofthe same, reference being had to the accompanying drawings, forming apart of this specification, and in whichy Figure l represents a sideview of my'improved wrench, and Fig. 2 represents a longitudinal sectionthereof.

In the drawings, A represents the stationary jaw; B, the shank uponwhich the movablejaw, C slides when operated upon by the male screw D.

E is the ferrule in which the rear end, a, of the male screw D rests.

F is the rosette grooved out and fitted to work into the parallelgrooves b b in the shank B, whereby all strain upon the ferrule E istransferred to the shank B, when the wrench is used in the ordinarymanner.

The rear sides of the grooves b b are perpendicular, while their frontsides are inclined, all as fully shown in the drawings, and.particularlyT Fig. 2.

The projections c c of the rosette Fy are also formed with perpendicularrear sides, and inclined or beveled front sides. In a previousinvention, for which I have applied for Letters Patent, the sides of thegrooves were perpendicular, both in front as well as in the rear, theobject of the grooves being to relieve the ferrule ofthe back strainfrom the'rosette. It is important that the rear sides should beperpendicular, since the strain in holding the jaw G- to its work comesupon two such surfaces.

The front sides have to bear considerable strain and abrasion inpounding, or when the wrench is used as a hammer, since the motion andforce of blow both tend to throw the movable jaw forward, and withinclined or beveled surfaces, as shown in the drawings, there is lessliability of the edges heading up, Ste., than with the perpendicularsides, besides the projections b b and cl are, for a given amount ofmetal, stronger and more effective than they would be with perpendicularsides in front as well as in the rear.

Having described my improved wrench, what I claim as of my invention,and desire to secure by Letters Patent, is-

The combination, in a wrench in which the strain is transferred from theferrule to the shank, as described, of one or more grooves, b, withperpendicular rear and beveled or inclined front side or sides, with oneor more projections, o, of corresponding form, on the rosette F,substantially as and for the purposes set forth.

GEO. C. TAFT.

Witnesses:

DANIEL STEATTON, J AMEs H. BANGROET.

